74 Dart Wiring diagram

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Austin Schlegel

Austin Schlegel

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Hi,

I have a 74 Dart sport 360 that is having some electrical issues. The altenator wont charge the battery and the key wont start the car (have to start from starter relay, with key in run position).

Does anyone have the wiring diagram for these components?

Thanks in advance
 
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Factory Service Manuals, with wiring diagrams, are available at Mymopar.com . Free downloads.
 
Or you can buy a color coded, laminated diagram.
It is much easier to read than black and white.
ClassicCarWiring.Com Home of the original color laminated diagrams

Screenshot_20211029-070813_Gallery.jpg
 
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Or you can just put in 74 dart on Google and pull up images and find it and save it and go to an office Depot and have them print it out in large form and even color for less than a couple dollars.. like I did..
On another note this is the same thing that was happening with my son for a couple months till I made him go buy a test light and we figured out it was just a loose connection at the starter solenoid...
 
Professor Fate said:
Factory Service Manuals, with wiring diagrams, are available at Mymopar.com . Free downloads.
Click to expand...

There are no complete diagrams there for 74, and 73 is different. MyMopar does have the aftermarket 2 page diagram WHICH can be easier to follow BUT is not complete, does not show all options, or the seat belt stuff

OP I created a reduced size diagram which you can download, "it may" have a problem let me know

This thread go to post no. 64. Right click the icon in the post and "save as." It is a pdf
 
So far as the no start problem this is very likely the SEAT BELT interlock. To fix that permanently, locate the "reset" box on the driver side fender apron, and splice the two yellow wires together. This device, when tripped, interrupts the yellow "start" wire which comes from the key and feeds to the starter relay

100_0894-jpg-jpg-jpg.jpg


16kx4d2-jpg.jpg
 
Charging system: These are fairly simple, basic diagram. This was envolved with a conversion so ignore where it says "existing wire." Basically, power from the key is fed to the "top of the point" of the VR connector, blue. The VR controls the "grounding" of the field of the alternator to control charge. That path for the field is from the key, to the field (blue) and through the field, and over to the VR (green) which controls ground

chrysler_external_voltage_regulator_wiring.jpg


For a couple of quick checks, disconnect the green wire from the alternator and ground that alternator terminal with a jumper wire. Start and run the engine, slowly bring up RPM while monitoring battery voltage and while monitoring the ammeter in the car

Voltage should come up from 12-ish to 14 or more. Don't allow it over 16

If this happens the alternator is likely OK. Now check the green wire for continuity back to the VR connector, and......

Make ABSOLUTELY certain the VR is GROUNDED

Pull the VR connector, inspect for corrosion, and work connector in/ out several times to "scrub" the terminals. Then check that the blue wire for the VR plug has power
 
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67Dart273 said:
So far as the no start problem this is very likely the SEAT BELT interlock. To fix that permanently, locate the "reset" box on the driver side fender apron, and splice the two yellow wires together. This device, when tripped, interrupts the yellow "start" wire which comes from the key and feeds to the starter relay

View attachment 1715811758

View attachment 1715811759
Click to expand...

I think you might be on to something there. I was looking for the seat belt interlock but could not find one on the drivers side fender apron. Although, I see wire connections that look like they may go to the box you've shown. If I am missing the reset box entirely is there a way to start without it?

View attachment 1715811762

1028211121.jpg


Edit: let me know if thats not a clear picture
 
Yes, splice the two yellows together as I said. That box switches them "off" so to say so if the box is not there, it will not crank
 
67Dart273 said:
Yes, splice the two yellows together as I said. That box switches them "off" so to say so if the box is not there, it will not crank
Click to expand...
Ok I am now getting 12v from the neutral safety wire. The ns switch still wont send 12v to the starter relay though. Thinking maybe its just the ns switch becuase I also get the 12v from ignition switch in the run position. I am going to the parts store to pick one up now just too see.
 
?? Pick what up?

The NS switch provides a ground in park or reverse. The path is key---start position--12v from yellow wire--through interlock box--to starter relay ---out starter relay---down to center pin of NSS--ground in park / neutral
 
I doubt you need one. The reset box unplugged is "number 1"
 
You're right I just tested the relay and it works fine. Im just confused as to how the relay is activated. So I need to be sure that the center pin of the the NSS is ground right? I'm thinking I don't have a complete circuit.
 
Austin Schlegel said:
You're right I just tested the relay and it works fine. Im just confused as to how the relay is activated. So I need to be sure that the center pin of the the NSS is ground right? I'm thinking I don't have a complete circuit.
Click to expand...

What I said earlier.......

67Dart273 said:
?? Pick what up?

The NS switch provides a ground in park or reverse. The path is key---start position--12v from yellow wire--through interlock box--to starter relay ---out starter relay---down to center pin of NSS--ground in park / neutral
Click to expand...

The two small push on "flag" terminals are the coil. You need to get the two yellows spliced there at the connector lying loose where that reset box belonged. Read again the "path" which is from key to relay to NSS. Yes, the center pin grounds in park or neutral. A quick easy check is to pull the NSS wire off and ground it, then see if it works with the key. BE CAREFUL doing this because it will crank "in gear"
 
So I disconnected the nss connecter (black wire) from the starter relay and then connected the nss flag terminal to neg battery and it cranked over
 
67Dart273 said:
Charging system: These are fairly simple, basic diagram. This was envolved with a conversion so ignore where it says "existing wire." Basically, power from the key is fed to the "top of the point" of the VR connector, blue. The VR controls the "grounding" of the field of the alternator to control charge. That path for the field is from the key, to the field (blue) and through the field, and over to the VR (green) which controls ground

View attachment 1715811760

For a couple of quick checks, disconnect the green wire from the alternator and ground that alternator terminal with a jumper wire. Start and run the engine, slowly bring up RPM while monitoring battery voltage and while monitoring the ammeter in the car

Voltage should come up from 12-ish to 14 or more. Don't allow it over 16

If this happens the alternator is likely OK. Now check the green wire for continuity back to the VR connector, and......

Make ABSOLUTELY certain the VR is GROUNDED

Pull the VR connector, inspect for corrosion, and work connector in/ out several times to "scrub" the terminals. Then check that the blue wire for the VR plug has power
Click to expand...

I have tried your steps and with the green feild connector grounded it is not getting above 12.5V at the battery. I then checked the blue field wire and it was getting 12v as expected. VR is also grounded. Then tested the output terminal of the alt and it was not outputing any voltage... So bad alternator maybe?
 
OK under what conditions did you check output? Was this with the one field grounded?
 
67 Dart, do some of the seatbelt interlocks have 3 yellow wires?
 
Update on the battery situation. I connected the pos battery post directly too the alt output post with a new wire and the battery is charging. Thinking maybe I have a blown fusible link between the battery and the alternator.
 
This can be one or more of several problems. The alternator output "path" is:

Alternator output..........charging wire........TO SUSPECT WHITE UNDERHOOD CONNECTOR......to bulkhead connector........BLACK to ammeter.........out ammeter on RED.......out through bulkhead connector.........fuse link.........starter relay "big stud"........and to battery

ANY of thoses points there including the wire ends at the alternator, any of the connectors and the wire ends at the ammeter AND the ammeter itself can be to blame.
 
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